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Xunxiang Hu, a Eugene P. Wigner Fellow in ORNL’s Materials Science and Technology Division, designed this machine to produce large, crack-free pieces of yttrium hydride to be used as a moderator in the core of ORNL’s Transformational Challenge Reactor and other microreactors. Credit: Xunxiang Hu/ORNL, U.S. Dept. of Energy

About 60 years ago, scientists discovered that a certain rare earth metal-hydrogen mixture, yttrium, could be the ideal moderator to go inside small, gas-cooled nuclear reactors.

At the U.S. Department of Energy Manufacturing Demonstration Facility at ORNL, this part for a scaled-down prototype of a reactor was produced for industry partner Kairos Power.

Scientists at the Department of Energy Manufacturing Demonstration Facility at ORNL have their eyes on the prize: the Transformational Challenge Reactor, or TCR, a microreactor built using 3D printing and other new approaches that will be up and running by 2023.

Scanning probe microscopes use an atom-sharp tip—only a few nanometers thick—to image materials on a nanometer length scale. The probe tip, invisible to the eye, is attached to a cantilever (pictured) that moves across material surfaces like the tone arm on a record player. Credit: Genevieve Martin/Oak Ridge National Laboratory; U.S. Dept. of Energy.

Liam Collins was drawn to study physics to understand “hidden things” and honed his expertise in microscopy so that he could bring them to light.